Display module and display device

ABSTRACT

A display module of the present disclosure includes a display module main body and a housing. The display module main body includes a first, a second display element, and a prism. The housing includes a first, and a second frame. The first frame holds the first display element in a state in which the prism is positioned between a first and a second plate portion, and in which a third plate portion is in contact with the first display element and faces a first surface, and the second frame holds the second display element in a state in which the prism is positioned between a fourth and a fifth plate portion, and in which a sixth plate portion is in contact with the second display element and faces a second surface.

The present application is based on, and claims priority from JPApplication Serial Number 2019-042644, filed Mar. 8, 2019, thedisclosure of which is hereby incorporated by reference herein in itsentirety.

BACKGROUND 1. Technical Field

The present disclosure relates to a display module and a display device.

2. Related Art

In recent years, a display device, such as a head-mounted display or ahead-up display, is provided that projects a virtual image in a space infront of an eye of an observer and allows the observer to visuallyrecognize the virtual image.

JP-A-2014-186201, which will be described below, discloses ahead-mounted display including an image element configured by a liquidcrystal panel, a case in which the image element is housed, a projectionoptical system that projects light from the image element, a lens barrelthat houses the projection optical system, and a light guiding devicethat guides the light from the projection optical system to an eye of anobserver. In this head-mounted display, the case in which the imageelement is housed is fixed to the lens barrel, and as a result, theimage element and the projection optical system are aligned with eachother.

In the above-described JP-A-2014-186201, a structure is disclosed inwhich the single image element is fixed to the lens barrel. In contrast,in the field of projectors, for example, a display module is known thatincludes a plurality of display panels that emit red light, green light,and blue light, respectively, and a color synthesis element thatsynthesizes the plurality of color light emitted from the plurality ofdisplay panels.

In this type of display module, precise alignment of the plurality ofdisplay panels is important to ensure display quality. In addition, whenapplying this type of display module to a display device, such as ahead-mounted display, there is a greater need to accommodate the displaymodule in a housing of a limited size, and it is thus required to have acompact configuration. However, a display module that allows easyalignment of the plurality of display panels and has a compactconfiguration, is not currently available.

SUMMARY

In order to solve the above-described problems, a display moduleaccording to an aspect of the present disclosure includes a displaymodule main body; and a housing provided to the display module mainbody. The display module main body includes a first display element, asecond display element, and a prism configured to synthesize first lightemitted from the first display element and second light emitted from thesecond display element, and the housing includes a first frame thatholds the first display element in a state in which the first displayelement faces a first surface of the prism, and a second frame thatholds the second display element in a state in which the second displayelement faces a second surface of the prism. The first frame includes afirst plate portion and a second plate portion facing each other, and athird plate portion that couples the first plate portion and the secondplate portion to each other, the second frame includes a fourth plateportion and a fifth plate portion facing each other, and a sixth plateportion that couples the fourth plate portion and the fifth plateportion to each other, and at least one of the first frame and thesecond frame includes an attachment portion for attaching the displaymodule main body to a support member. The first frame holds the firstdisplay element in a state in which the prism is positioned between thefirst plate portion and the second plate portion, and in which the thirdplate portion is in contact with the first display element and faces thefirst surface, and the second frame holds the second display element ina state in which the prism is positioned between the fourth plateportion and the fifth plate portion, and in which the sixth plateportion is in contact with the second display element and faces thesecond surface.

In the display module according to an aspect of the present disclosure,the first frame and the second frame may contain a metal material, thefirst frame and the first display element may be thermally coupled, andthe second frame and the second display element may be thermallycoupled.

In the display module according to an aspect of the present disclosure,each of the first plate portion and the second plate portion of thefirst frame may be provided with a step portion that defines, by cominginto contact with a portion of the first surface of the prism, adistance between the first display element and the first surface, andeach of the fourth plate portion and the fifth plate portion of thesecond frame may be provided with a step portion that defines, by cominginto contact with a portion of the second surface of the prism, adistance between the second display element and the second surface.

In the display module according to an aspect of the present disclosure,the display module main body may further include a third displayelement, the prism may synthesize the first light, the second light, andthird light emitted from the third display element, and the housing mayfurther include a third frame that holds the third display element in astate in which the third display element faces a third surface of theprism. The third frame may include a seventh plate portion and an eighthplate portion facing each other, and a ninth plate portion that couplesthe seventh plate portion and the eighth plate portion to each other,and the third frame may hold the third display element in a state inwhich the prism is positioned between the seventh plate portion and theeighth plate portion, and in which the third plate portion is in contactwith the third display element and faces the third surface.

In the display module according to an aspect of the present disclosure,the third frame may contain metal material, and the third frame and thethird display element may be thermally coupled.

In the display module according to an aspect of the present disclosure,each of the seventh plate portion and the eighth plate portion of thethird frame may be provided with a step portion that defines, by cominginto contact with a portion of the third surface of the prism, adistance between the third display element and the third surface.

In the display module according to an aspect of the present disclosure,the first surface and the second surface of the prism may face eachother, the third surface may be positioned in a direction intersectingthe first surface and the second surface, and a first clamping portionor a second clamping portion may be provided, the first clamping portionbeing configured such that a portion of the seventh plate portion andthe prism clamp a portion of the first plate portion and a portion ofthe fourth plate portion, and the second clamping portion beingconfigured such that a portion of the eighth plate portion and the prismclamp a portion of the second plate portion and a portion of the fifthplate portion.

In the display module according to an aspect of the present disclosure,one of the first clamping portion and the second clamping portion may beprovided with a through hole, and the through hole may be providedtherein with a coupling member coupling the first frame and the thirdframe, and coupling the second frame and the third frame.

In the display module according to an aspect of the present disclosure,one of the first clamping portion and the second clamping portion may beprovided with fitting portions that couple, by fitting to each other,the first frame and the third frame, and couple the second frame and thethird frame.

In the display module according to an aspect of the present disclosure,the attachment portion may be provided in each of the first frame andthe second frame.

In the display module according to an aspect of the present disclosure,the attachment portion may be provided with a positional adjustmentmechanism for adjusting a position of the display module main body withrespect to the support member.

A display device according to an aspect of the present disclosureincludes the display module according to an aspect of the presentdisclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a display module according to a firstembodiment.

FIG. 2 is a perspective view illustrating a state in which the displaymodule is attached to a support member.

FIG. 3 is a perspective view of a display module main body.

FIG. 4A is a perspective view illustrating a state before attaching ablue panel frame to the display module main body.

FIG. 4B is a perspective view illustrating a state after attaching theblue panel frame to the display module main body.

FIG. 5 is a perspective view illustrating a state after attaching theblue panel frame and a red panel frame to the display module main body.

FIG. 6A is a perspective view illustrating a state before attaching agreen panel frame to the display module main body.

FIG. 6B is a perspective view illustrating a state after attaching thegreen panel frame to the display module main body.

FIG. 7 is a perspective view illustrating a state before attachingfixing pins to the display module main body.

FIG. 8 is a front view illustrating the state in which the displaymodule is attached to the support member.

FIG. 9 is an enlarged view of a position adjustment mechanism.

FIG. 10 is a schematic configuration view illustrating a head-mounteddisplay device according to a second embodiment.

FIG. 11 is a perspective view schematically illustrating an opticalsystem of the display device illustrated in FIG. 10.

FIG. 12 is a diagram illustrating optical paths of the optical systemillustrated in FIG. 11.

DESCRIPTION OF EXEMPLARY EMBODIMENTS First Embodiment

A first embodiment of the present disclosure will be described belowwith reference to FIG. 1 to FIG. 10.

In the first embodiment, a display module provided with three displaypanels and a prism will be described as an example.

In each of the drawings below, dimensions of some components may bescaled differently for ease of visual understanding of each of thecomponents.

FIG. 1 is a perspective view of a display module 10 of the firstembodiment.

As illustrated in FIG. 1, the display module 10 includes a displaymodule main body 11 and a housing 12 provided on the display module mainbody 11.

FIG. 2 is a perspective view illustrating a state in which the displaymodule 10 is attached to a subframe 90 (a support member) of a displaydevice.

The display module 10 is used in a display device, such as ahead-mounted display, a head-up display, and the like. When the displaymodule 10 is mounted on the display device, as illustrated in FIG. 2,the display module 10 is attached to a chosen support member configuringthe display device, via a first attachment portion and a secondattachment portion, which will be described later. In this embodiment,the subframe 90 accommodating a light guiding optical system, which is asubsequent stage of the display module 10, is used as the supportmember, but the support member to which the display module 10 is fixedis not particularly limited.

FIG. 3 is a perspective view of the display module main body 11.

As illustrated in FIG. 3, the display module main body 11 includes ablue display panel 14B (a first display element), a red display panel14R (a second display element), a green display panel 14G (a thirddisplay element), and a prism 15. The blue display panel 14B emits bluelight (first light). The red display panel 14R emits red light (secondlight). The green display panel 14G emits green light (third light). Theprism 15 synthesizes the blue light emitted from the blue display panel14B, the red light emitted from the red display panel 14R, and the greenlight emitted from the green display panel 14G.

The blue display panel 14B, the red display panel 14R, and the greendisplay panel 14G differ from each other in terms of the color of theemitted light, namely, the display color, but have substantially thesame configuration. Thus, in the following description, these displaypanels 14B, 14R, 14G will be simply referred to as a display panel, anda configuration of a display panel 14 will be described.

The display panel 14 includes an element substrate 16 and a sealingsubstrate 17. A first surface of the element substrate 16 is providedwith a plurality of organic electroluminescence (EL) elements arrangedin a matrix pattern. Each of the plurality of organic EL elementsconfigures a pixel, and a region in which the plurality of organic ELelements are arranged in the matrix pattern is an image display region.An image of each of the colors is formed by controllingemission/non-emission of each of the organic EL elements on the elementsubstrate 16 corresponding to each of the colors. The element substrate16 is formed by a semiconductor substrate made of silicon and the like,for example.

The sealing substrate 17 is provided facing the first surface of theelement substrate 16. By covering the plurality of organic EL elements,the sealing substrate 17 inhibits moisture, dust, and the like fromentering a formation region of the plurality of organic EL elements. Thesealing substrate 17 is formed by a transparent substrate made of glassand the like, for example.

The prism 15 is provided with four triangular prismatic prisms 151 andtwo dichroic mirrors 152 and 153. The prism 15 has a configuration inwhich the four triangular prismatic prisms 151 are adhered to eachother, and has a substantially rectangular parallelepiped shape as awhole. The two dichroic mirrors 152 and 153 are each provided onadhesion surfaces of the triangular prismatic prisms 151. Of sixsurfaces forming the outer shape of the rectangular parallelepiped prism15, a surface facing the blue display panel 14B is a first surface 15 a,a surface facing the red display panel 14R is a second surface 15 b, anda surface facing the green display panel 14G is a third surface 15 c.The first surface 15 a and the second surface 15 b face each other, anda surface facing the third surface 15 c is a fourth surface 15 d. Theremaining two surfaces are a fifth surface 15 e and a sixth surface 15f, respectively.

When the prism 15 is viewed from the normal direction of the fifthsurface 15 e or of the sixth surface 15 f, the two dichroic mirrors 152and 153 are provided intersecting each other so as to form an X shape inthe fifth surface 15 e or the sixth surface 15 f. The first dichroicmirror 152 has characteristics of reflecting the blue light andtransmitting the green light and the red light. The second dichroicmirror 153 has characteristics of reflecting the red light andtransmitting the green light and the blue light.

The blue light emitted from the blue display panel 14B is incident onthe prism 15 from the first surface 15 a. The red light emitted from thered display panel 14R is incident on the prism 15 from the secondsurface 15 b. The green light emitted from the green display panel 14Gis incident on the prism 15 from the third surface 15 c. The blue lightincident on the prism 15 is reflected by the first dichroic mirror 152and travels toward the fourth surface 15 d. The red light incident onthe prism 15 is reflected by the second dichroic mirror 153 and travelstoward the fourth surface 15 d. The green light incident on the prism 15is transmitted through the first dichroic mirror 152 and the seconddichroic mirror 153, and travels toward the fourth surface 15 d. In thisway, the prism 15 synthesizes the blue light emitted from the bluedisplay panel 14B, the red light emitted from the red display panel 14R,and the green light emitted from the green display panel 14G. Thesynthesized light is emitted from the fourth surface 15 d of the prism15.

In this embodiment, each of the display panels 14 is fixed to the prism15 via an optical adhesive (not illustrated) so that the sealingsubstrate 17 faces each of the surfaces of the prism 15. Thus, the bluedisplay panel 14B is provided so that the sealing substrate 17 comesinto contact with the first surface 15 a of the prism 15 via the opticaladhesive. The red display panel 14R is provided so that the sealingsubstrate 17 comes into contact with the second surface 15 b of theprism 15 via the optical adhesive. The green display panel 14G isprovided so that the sealing substrate 17 comes into contact with thethird surface 15 c of the prism 15 via the optical adhesive.

Light emitted from the organic EL element is not emitted from theelement substrate 16 that is not transmissive, but is emitted from thesealing substrate 17 that is transmissive, and is incident on the prism15. Note that each of the display panels 14 need not necessarily be incontact with each of the surfaces of the prism 15 via the opticaladhesive, but may be in contact with each of the surfaces of the prism15 without having the optical adhesive interposed therebetween. Further,each of the display panels 14 may be disposed so as to be separated fromthe prism 15 in a state of being held by the housing 12. That is, a gapmay be provided between each of the display panels 14 and each of thesurfaces of the prism 15.

In each of the display panels 14, the element substrate 16 is disposedso that one end portion of the element substrate 16 does not face theprism 15 and protrudes outward from the prism 15. Of the elementsubstrate 16, a region of the one end portion that does not face theprism 15 is a region that is outside the image display region and is aregion in which a circuit, a wiring line, an external connectionterminal, and the like for driving a plurality of the pixels areprovided. Further, an external circuit board, such as a flexible printedcircuit board (FPC) on which a driving circuit element is mounted, maybe coupled to the external connection terminal. In this embodiment, theshape of the element substrate 16 is a rectangular shape, and of foursides of the element substrate 16, two sides, a portion of each of whichprotrudes outward, are defined as first sides 16 a, and two sidesorthogonal to the first sides 16 a are defined as second sides 16 b.

The blue display panel 14B is disposed so that the one end portion ofthe element substrate 16 protrudes toward a light emission side of thesynthesized light (the outer side of the fourth surface 15 d of theprism 15). In contrast to the blue display panel 14B, the red displaypanel 14R is disposed so that the one end portion of the elementsubstrate 16 protrudes toward the opposite side (the outer side of thethird surface 15 c of the prism 15) to the light emission side of thesynthesized light. The green display panel 14G is disposed so that theone end of the element substrate 16 protrudes toward the side of theblue display panel 14B (the outer side of the first surface 15 a of theprism 15). Specifically, when the display module main body 11 is viewedfrom the side of the fifth surface 15 e, the blue display panel 14Bprotrudes from the prism 15 to the left side, the red display panel 14Rprotrudes from the prism 15 to the right side, and the green displaypanel 14G protrudes from the prism 15 to the upper side. With thisarrangement, it is possible to reduce the size of the prism 15. However,the arrangement of each of the display panels 14 is not limited to thisexample, and may be changed as appropriate.

As illustrated in FIG. 1. and FIG. 2, the housing 12 includes a bluepanel frame 19B (a first frame), a red panel frame 19R (a second frame),a green panel frame 19G (a third frame), and a plurality of fixing pins21 (coupling members). The blue panel frame 19B holds the blue displaypanel 14B in a state in which the blue display panel 14B faces the firstsurface 15 a of the prism 15. The red panel frame 19R holds the reddisplay panel 14R in a state in which the red display panel 14R facesthe second surface 15 b of the prism 15. The green panel frame 19G holdsthe green display panel 14G in a state in which the green display panel14G faces the third surface 15 c of the prism 15.

A detailed configuration of each of the frames 19B, 19R, and 19G will bedescribed below along with an assembly process of the display module 10.

FIG. 4A is a perspective view illustrating a state before attaching theblue panel frame 19B to the display module main body 11. FIG. 4B is aperspective view illustrating a state after attaching the blue panelframe 19B to the display module main body 11.

FIG. 5 is a perspective view illustrating a state after attaching theblue panel frame 19B and the red panel frame 19R to the display modulemain body 11.

FIG. 6A is a perspective view illustrating a state before attaching thegreen panel frame 19G to the display module main body 11. FIG. 6B is aperspective view illustrating a state after attaching the green panelframe 19G to the display module main body 11.

FIG. 7 is a perspective view illustrating a state before attaching thefixing pins 21 to the display module main body 11.

The assembly process according to this embodiment will be describedusing an example in which each of the blue display panel 14B, the reddisplay panel 14R, and the green display panel 14G is temporarily fixedto the prism 15 in advance, before attaching each of the frames 19B,19R, and 19G to the display module main body 11.

As illustrated in FIG. 4A, the blue panel frame 19B includes a firstplate portion 19B1 and a second plate portion 19B2 that face each other,a third plate portion 19B3 that couples the first plate portion 19B1 andthe second plate portion 19B2, and a first attachment portion 19B0. Thefirst plate portion 19B1, the second plate portion 19B2, the third plateportion 19B3, and the first attachment portion 19B0 are formed from onepiece of a plate material. The first plate portion 19B1 and the thirdplate portion 19B3 are formed to form an angle of approximately 90°. Thesecond plate portion 19B2 and the third plate portion 19B3 are formed toform an angle of approximately 90°. As a result, the prism 15 isaccommodated in a space surrounded by the first plate portion 19B1, thesecond plate portion 19B2, and the third plate portion 19B3. The bluepanel frame 19B is formed from, for example, a metal material such asaluminum, titanium, magnesium, and alloys of these metals, or a plasticcontaining carbon fibers.

Hereinafter, the space surrounded by the first plate portion 19B1, thesecond plate portion 19B2, and the third plate portion 19B3, and inwhich the prism 15 is accommodated will be referred to as anaccommodating space S1. Further, of surfaces of the first plate portion19B1, the second plate portion 19B2, and the third plate portion 19B3, asurface on a side facing the accommodating space S1 is referred to as afirst surface 19Ba, and a surface on the opposite side to the firstsurface 19Ba is referred to as a second surface 19Bb.

The first plate portion 19B1 has a trapezoidal shape when viewed fromthe normal direction of the second surface 19Bb of the first plateportion 19B1. In other words, of the four sides of the trapezoid thatforms the outer shape of the first plate portion 19B1, a second side 19b 2 opposite to a first side 19 b 1, which is a side coupled to thethird plate portion 19B3, extends obliquely with respect to the firstside 19 b 1. The remaining sides, namely, a third side 19 b 3 and afourth side 19 b 4 are parallel to each other and extend perpendicularlywith respect to the first side 19 b 1. A through hole 19 b 5 penetratingthrough the first plate portion 19B1 in the plate thickness direction isprovided in the vicinity of a corner portion in which the second side 19b 2 and the third side 19 b 3 meet at an acute angle.

Further, the first surface 19Ba of the first plate portion 19B1 isprovided with a step portion 19 b 6 that protrudes toward theaccommodating space S1 side. A dimension W1 of the second side 16 b ofthe blue display panel 14B is shorter than a dimension W2 of one side ofthe prism 15 parallel to the second side 16 b. In other words, W1<W2.Thus, of the first surface 15 a of the prism 15, regions on both sidesof a region to which the blue display panel 14B is bonded become exposedsections that are exposed from the blue display panel 14B. In a state inwhich the blue panel frame 19B is attached to the display module mainbody 11, the step portion 19 b 6 comes into contact with the exposedsection of the first surface 15 a of the prism 15.

Further, a dimension L1 from the first surface 19Ba of the third plateportion 19B3 to the step portion 19 b 6 is substantially equal to athickness T1 of the blue display panel 14B. In other words, L1=T1.Strictly speaking, the dimension L1 from the first surface 19Ba of thethird plate portion 19B3 to the step portion 19 b 6 is equal to a totalthickness of the thickness T1 of the blue display panel 14B and thethickness of the optical adhesive.

In this case, as illustrated in FIG. 4B, when the step portion 19 b 6 isbrought into contact with a portion of the first surface 15 a of theprism 15, the first surface 19Ba of the third plate portion 19B3 comesinto contact with the blue display panel 14B. In other words, in thecase of this embodiment, since the first surface 19Ba of the third plateportion 19B3 and the blue display panel 14B are in contact with eachother, the blue display panel 14B comes into contact with the firstsurface 15 a of the prism 15. Specifically, a distance between the bluedisplay panel 14B and the first surface 15 a of the prism 15 becomeszero.

As will be described below, although the blue display panel 14B and thethird plate portion 19B3 are required be in contact with each other froma perspective of thermal conduction, the blue display panel 14B and theprism 15 need not necessarily be in contact with each other, and theremay be a gap between the blue display panel 14B and the first surface 15a of the prism 15. When a gap is provided between the blue display panel14B and the prism 15, the dimension L1 from the first surface 19Ba ofthe third plate portion 19B3 to the step portion 19 b 6 is set to beequal to a dimension obtained by adding the dimension of the gap to thethickness T1 of the blue display panel 14B. In this way, the stepportion 19 b 6 defines the distance between the blue display panel 14Band the first surface 15 a of the prism 15 by coming into contact withthe portion of the first surface 15 a of the prism 15.

As illustrated in FIG. 4A, the second plate portion 19B2 has the sameconfiguration as the first plate portion 19B1. The second plate portion19B2 is provided symmetrically with respect to the first plate portion19B1 on an end portion of the third plate portion 19B3 on the oppositeside to the side on which the first plate portion 19B1 is provided.Thus, a description of the second plate portion 19B2 is omitted here.

The first attachment portion 19B0 is provided along the edge of thesecond surface 19Bb of the third plate portion 19B3. The firstattachment portion 19B0 is configured by a wall portion protruding fromthe second surface 19Bb of the third plate portion 19B3. The firstattachment portion 19B0 is configured as a member integrally formed withthe third plate portion 19B3. A through hole 1967 penetrating throughthe first attachment portion 19B0 in a direction along the secondsurface 19Bb of the third plate portion 19B3 is provided in the firstattachment portion 19B0. The first attachment portion 19B0 functions asa member for attaching the display module main body 11 to the supportmember.

As illustrated in FIG. 5, the red panel frame 19R includes a fourthplate portion 19R4 and a fifth plate portion 19R5 that face each other,a sixth plate portion 19R6 that couples the fourth plate portion 19R4and the fifth plate portion 19R5, and a second attachment portion 19R0.Further, both a through hole 19 r 5 and a step portion 19 r 6 areprovided in each of the fourth plate portion 19R4 and the fifth plateportion 19R5. A through hole 19 r 7 is provided in the second attachmentpart 19R0. In this way, the red panel frame 19R has the sameconfiguration as the blue panel frame 19B. Thus, a detailed descriptionof each portion of the red panel frame 19R is omitted here.

As illustrated in FIG. 6A, the green panel frame 19G includes a seventhplate portion 19G7 and an eighth plate portion 19G8 that face eachother, and a ninth plate portion 19G9 that couples the seventh plateportion 19G7 and the eighth plate portion 19G8. In the green panel frame19G, the display module main body 11 is accommodated in a space S2surrounded by the seventh plate portion 19G7, the eighth plate portion19G8, and the ninth plate portion 19G9. Similarly to the blue panelframe 19B, the green panel frame 19G is formed from, for example, ametal material such as aluminum, titanium, magnesium, and alloys ofthese metals, or a plastic containing carbon fibers.

Hereinafter, the space which is surrounded by the seventh plate portion19G7, the eighth plate portion 19G8, and the ninth plate portion 19G9,and in which the display module main body 11 is accommodated will bereferred to as the accommodating space S2. Further, of surfaces of theseventh plate portion 19G7, the eighth plate portion 19G8, and the ninthplate portion 19G9, a surface on a side facing the accommodating spaceS2 is referred to as a first surface 19Ga, and a surface on the oppositeside to the first surface 19Ga is referred to as a second surface 19Gb.

The seventh plate portion 19G7 has a rectangular shape when viewed fromthe normal direction of the second surface 19Gb of the seventh plateportion 19G7. In other words, of the four rectangular sides forming theouter shape of the seventh plate portion 19G7, a second side 19 g 2facing a first side 19 g 1, which is a side coupled to the ninth plateportion 19G9, extends in parallel to the first side 19 g 1. A third side19 g 3 and a fourth side 19 g 4 are parallel to each other and extendperpendicularly with respect to the first side 19 g 1 and the secondside 19 g 2. Through holes 19 g 5 penetrating through the seventh plateportion 19G7 in the plate thickness direction are respectively providedin the vicinity of a corner portion in which the second side 19 g 2 andthe third side 19 g 3 meet and a corner portion in which the second side19 g 2 and the fourth side 19 g 4 meet.

Further, in the first surface 19Ga of the seventh plate portion 19G7, afirst step portion 19 g 7 that protrudes toward the accommodating spaceS2 side is provided. When viewed from the normal direction of the firstsurface 19Ga of the seventh plate portion 19G7, the first step portion19 g 7 is provided so as to form an isosceles triangular shape havingthe bottom side on a side of the first side 19 g 1 of the seventh plateportion 19G7 and the apex on a side of the second side 19 g 2. An apexangle α1 of the isosceles triangle forming the shape of the first stepportion 19 g 7 matches an apex angle α2 of an isosceles triangle formedby the second side 19 b 2 of the first plate portion 19B1 and the secondside 19 r 2 of the fourth plate portion 19R4 when the blue panel frame19B and the red panel frame 19R are attached to the display module mainbody 11. In this case, the first step portion 19 g 7 comes into contactwith an end face of the first plate portion 19B1 and an end face of thefourth plate portion 19R4. However, the apex angle α1 need notnecessarily match the apex angle α2, and may be smaller than the apexangle α2. In this case, the first step portion 19 g 7 does not come intocontact with the end face of the first plate portion 19B1 and the endface of the fourth plate portion 19R4.

Further, in the first surface 19Ga of the seventh plate portion 19G7, asecond step portion 19 g 8 that protrudes further from the first stepportion 19 g 7 toward the accommodating space S2 side is provided. Thesecond step portion 19 g 8 has a similar configuration and a similarfunction to the step portion 19 b 6 described above in relation to theblue panel frame 19B.

In other words, a dimension L3 from the first surface 19Ga of the ninthplate portion 19G9 to the second step portion 19 g 8 is substantiallyequal to a thickness T2 of the green display panel 14G. That is, L3≠T2.Strictly speaking, the dimension L3 from the first surface 19 Ga to thesecond stepped portion 19 g 8 of the ninth plate portion 19G9 is equalto a total thickness of the thickness T2 of the green display panel 14Gand the thickness of the optical adhesive.

In this case, as illustrated in FIG. 6B, when the second stepped portion19 g 8 is brought into contact with a portion of the third surface 15 cof the prism 15, the first surface 19Ga of the ninth plate portion 19G9comes into contact with the green display panel 14G. In other words, inthe case of the present embodiment, since the first surface 19Ga of theninth plate portion 19G9 and the green display panel 14G are in contactwith each other, the green display panel 14G and the third surface 15 cof the prism 15 also come into contact with other. Specifically, adistance between the green display panel 14G and the third surface 15 cof the prism 15 becomes zero. In this way, the second stage portion 19 g8 defines the distance between the green display panel 14G and the thirdsurface 15 c of the prism 15 by coming into contact with the portion ofthe third surface 15 c of the prism 15.

The eighth plate portion 19G8 has the same configuration as the seventhplate portion 19G7. The eighth plate portion 19G8 is providedsymmetrically with respect to the seventh plate portion 19G7 on an endportion of the ninth plate portion 19G9 on the opposite side to the sideon which the seventh plate portion 19G7 is provided. Thus, a descriptionof the eighth plate portion 19G8 is omitted here.

An example of the assembly process of the display module 10 will bedescribed below.

First Step

First, as illustrated in FIG. 3, the blue display panel 14B, the reddisplay panel 14R, and the green display panel 14G are temporarily fixedto the prism 15 using the optical adhesive. For example, anultraviolet-curable optical adhesive can be used as the opticaladhesive. In this step, each of the display panels 14 is roughly alignedwith the prism 15 using a chosen alignment mark or the like, forexample. Further, while keeping the optical adhesive from beingcompletely cured, a state is maintained in which relative positions ofthe blue display panel 14B, the red display panel 14R, and the greendisplay panel 14G with respect to the prism 15 can be finely adjusted.By this step, the display module main body 11 is manufactured.

Second Step

Next, as illustrated in FIG. 4A, the blue panel frame 19B is attached tothe display module main body 11. At this time, as illustrated in FIG.4B, the blue panel frame 19B is fitted into the display module main body11 up to a position at which the step portions 19 b 6 of the first plateportion 19B1 and the second plate portion 19B2 come into contact withthe first surface 15 a of the prism 15. At this time, a portion of thefirst plate portion 19B1 closer to a tip end side thereof than the stepportion 19 b 6 comes into contact with the fifth surface 15 e of theprism 15, a portion of the second plate portion 19B2 closer to a tip endside thereof than the step portion (not illustrated) of the second plateportion 19B2 comes into contact with the sixth surface 15 f of the prism15, and a state is obtained in which the first plate portion 19B1 andthe second plate portion 19B2 clamp the prism 15 from the outer sides ofthe fifth surface 15 e and the sixth surface 15 f. Since, in this way.there is no gap between the first plate portion 19B1 and the prism 15,and between the second plate portion 19B2 and the prism 15, the bluepanel frame 19B does not shift in the direction in which the first plateportion 19B1 and the second plate portion 19B2 face each other.

Further, the third plate portion 19B3 comes into contact with the bluedisplay panel 14B, and a state is obtained in which the third plateportion 19B3 presses the blue display panel 14B toward the prism 15. Inthis way, the blue panel frame 19B holds the blue display panel 14B in astate in which the prism 15 is positioned between the first plateportion 19B1 and the second plate portion 19B2, and the third plateportion 19B3 is in contact with the blue display panel 14B and faces thefirst surface 15 a of the prism 15. At this time, the blue panel frame19B and the blue display panel 14B are thermally coupled at the thirdplate portion 19B3.

Third Step

Next, the red panel frame 19R is attached to the display module mainbody 11. This attachment method is the same as the attachment method forthe blue panel frame 19B in the second step. In other words, asillustrated in FIG. 5, the red panel frame 19R is fitted into thedisplay module main body 11 from a direction opposite to the blue panelframe 19B up to a position at which the step portions 19 r 6 of thefourth plate portion 19R4 and the fifth plate portion 19R5 come intocontact with the second surface 15 b of the prism 15.

At this time, a portion of the fourth plate portion 19R4 closer to a tipend side thereof than the step portion 19 r 6 comes into contact withthe fifth surface 15 e of the prism 15, a portion of the fifth plateportion 19R5 closer to a tip end side thereof than the step portion 19 r6 comes into contact with the sixth surface 15 f of the prism 15, and astate is obtained in which the fourth plate portion 19R4 and the fifthplate portion 19R5 clamp the prism 15 from the outer sides of the fifthsurface 15 e and the sixth surface 15 f.

Further, the sixth plate portion 19R6 comes into contact with the reddisplay panel 14R, and the sixth plate portion 19R6 presses the reddisplay panel 14R toward the prism 15. In this way, the red panel frame19R holds the red display panel 14R in a state in which the prism 15 ispositioned between the fourth plate portion 19R4 and the fifth plateportion 19R5, and the sixth plate portion 19R6 is in contact with thered display panel 14R and faces the second surface 15 b of the prism 15.At this time, the red panel frame 19R and the red display panel 14R arethermally coupled in the sixth plate portion 19R6.

Note that the order in which the blue panel frame 19B and the red panelframe 19R are attached to the display module main body 11 is notparticularly limited, and may be a reversed order from the order in thisembodiment.

Fourth Step

Next, as illustrated in FIG. 6A, the green panel frame 19G is attachedto the display module main body 11. At this time, as illustrated in FIG.6B, the triangular first step portions 19 g 7 of the seventh plateportion 19G7 and the eighth plate portion 19G8 come into contact withthe end faces of the blue panel frame 19B and the end faces of the redpanel frame 19R, and the green panel frame 19G is fitted onto thedisplay module main body 11 up to a position at which the second stepportions 19 g 8 come into contact with portions of the third surface 15c of the prism 15.

At this time, a portion of the seventh plate portion 19G7 located insidethe triangle forming the outer shape of the first step portion 19 g 7 isin contact with the fifth surface 15 e of the prism 15, a portion of theeighth plate portion 19G8 located inside the triangle forming the outershape of the first step portion 19 g 7 is in contact with the sixthsurface of the prism 15, and a state is obtained in which the seventhplate portion 19G7 and the eighth plate portion 19G8 clamp the prism 15from the outer sides of the fifth surface 15 e and the sixth surface 15f. Since, in this way, there is no gap between the seventh plate portion19G7 and the prism 15, and between the eighth plate portion 19G8 and theprism 15, the green panel frame 19G does not shift in the direction inwhich the seventh plate portion 19G7 and the eighth plate portion 19G8face each other. Further, since the triangular-shaped first stepportions 19 g 7 of the seventh plate portion 19G7 and the eighth plateportion 19G8 fit into triangular-shaped recessed portions formed by theend faces of the blue panel frame 19B and the end faces of the red panelframe 19R, the green panel frame 19G does not shift in a directionorthogonal to the direction in which the seventh plate portion 19G7 andthe eighth plate portion 19G8 face each other.

On the other hand, when viewed from the normal direction of the seventhplate portion 19G7, a state is obtained in which a portion of theseventh plate portion 19G7 located outside the triangle forming theouter shape of the first step portion 19 g 7 overlaps with a portion ofthe first plate portion 19B1 of the blue panel frame 19B and a portionof the fourth plate portion 19R4 of the red panel frame 19R. As aresult, the portion of the seventh plate portion 19G7 and the prism 15clamp the portion of the first plate portion 19B1 and the portion of thefourth plate portion 19R4, and configure a first clamping portion 23 asillustrated in FIG. 6B.

Similarly, when viewed from the normal direction of the eighth plateportion 19G8, a portion of the eighth plate portion 19G8 located outsidethe triangle forming the outer shape of the first step portion 19 g 7overlaps with a portion of the second plate portion 19B2 of the bluepanel frame 19B and a portion of the fifth plate portion 19R5 of the redpanel frame 19R. As a result, the portion of the eighth plate portion19G8 and the prism 15 clamp the portion of the second plate portion 19B2and the portion of the fifth plate portion 19R5, and configure a secondclamping portion 24 as illustrated in FIG. 6B. In this way, the greenpanel frame 19G holds the blue panel frame 19B and the red panel frame19R.

Further, the green panel frame 19G holds the green display panel 14G ina state in which the prism 15 is positioned between the seventh plateportion 19G7 and the eighth plate portion 19G8, and the ninth plateportion 19G9 is in contact with the green display panel 14G and facesthe third surface 15 c of the prism 15. At this time, the green panelframe 19G and the green display panel 14G are thermally coupled at theninth plate portion 19G9.

Fifth Step

After attaching the green panel frame 19G to the display module mainbody 11, in the first clamping portion 23, the through hole 19 g 5 inthe seventh plate part 19G7 of the green panel frame 19G and the throughhole 19 b 5 in the first plate portion 19B1 of the blue panel frame 19Bare formed to be coaxially positioned and form a single continuousthrough-hole. Further, the through hole 19 g 5 in the eighth plateportion 19G8 of the green panel frame 19G and the through hole 19 b 5 inthe second plate portion 19B2 of the blue panel frame 19B, and thethrough-hole 19 g 5 in the eighth plate portion 19G8 of the green panelframe 19G and the through hole in the fifth plate portion 19R5 of thered panel frame 19R are also formed to be respectively coaxiallypositioned and form a single continuous through-hole, respectively.

Here, as illustrated in FIG. 7, a fixing pin 21 is inserted into each ofthe through holes 19 gb penetrating through the green panel frame 19Gand the blue panel frame 19B and each of the through holes 19 grpenetrating through the green panel frame 19G and the red panel frame19R, the through holes 19 gb and the through holes 19 gr being providedin the first clamping portion 23. Similarly, the fixing pin 21 isinserted into each of the through holes 19 gb penetrating through thegreen panel frame 19G and the blue panel frame 19B and each of thethrough holes 19 gr penetrating through the green panel frame 19G andthe red panel frame 19R, the through holes being provided in the secondclamping portion 24. As a result, a relative positional relationshipbetween the green panel frame 19G, the blue panel frame 19B, and the redpanel frame 19R is fixed, and the housing 12 is configured.

Sixth Step

Next, an adhesive is used to fix the housing 12 to the display modulemain body 11. At this time, it is desirable to apply the adhesive to thefifth surface 15 e and the sixth surface 15 f through which no lightenters or exits, of the six surfaces of the prism 15, and fix each ofthe frames 19B, 19R, and 19G configuring the housing 12 to the prism 15.However, the position to which the adhesive is applied is notparticularly limited.

Although the display module main body 11 and the housing 12 are fixed toeach other after this step is completed, since the optical adhesiveinterposed between each of the display panels 14B, 14R, and 14G, and theprism 15 is not completely cured, the position of each of the displaypanels 14B, 14R, and 14G can be moved within a range of a dimensionalmargin between each of the display panels 14B, 14R, and 14G, and each ofthe frames 19B, 19R, and 19G.

Seventh Step

Next, positional alignment between the blue display panel 14B, the reddisplay panel 14R, and the green display panel 14G is performed. At thistime, for example, a chosen alignment pattern may be displayed on eachof the display panels 14B, 14R, and 14G, and the position of each of thedisplay panels 14B, 14R, and 14G may be finely adjusted, while observingan overlapping state of the three alignment patterns from the side ofthe fourth surface 15 d of the prism 15 using a camera, so that thethree alignment patterns are matched up with each other at a pixellevel.

Eighth Step

Next, by completely curing the optical adhesive, each of the displaypanels 14B, 14R, and 14G is fixed to the prism 15.

By the above-described steps, the display module 10 of this embodimentis completed.

A configuration for attaching the display module 10 to the subframe 90(support member) of the display device will be described below.

FIG. 2 is a perspective view illustrating a state in which the displaymodule 10 is attached to the subframe 90. FIG. 8 is a front viewillustrating a state in which the display module 10 is attached to thesubframe 90. FIG. 9 is an enlarged view of a positional adjustmentmechanism 26.

As illustrated in FIG. 8 and FIG. 9, the display module 10 furtherincludes the positional adjustment mechanism 26 in addition to theabove-described display module main body 11 and housing 12. Thepositional adjustment mechanism 26 is used to adjust the position of thedisplay module 10 with respect to the subframe 90.

Here, an attachment surface 90 a of the subframe 90 to which the displaymodule 10 is attached is denoted as a XY plane, which functions as areference plane, two directions that are orthogonal to each other in theXY plane are defined as a X direction and a Y direction, and a directionorthogonal to the XY plane is defined as a Z direction. At this time,functions of the above-described positional adjustment mechanism 26 arespecifically described as follows. The positional adjustment mechanism26 adjusts each of four items that are (1) the position of the displaymodule 10 in the X and Y directions, (2) the rotation of the displaymodule 10 in the XY plane, (3) the inclination of the display module 10(a light emission surface of the prism 15) with respect to the XY plane,and (4) the position of the display module 10 in the Z direction.

The positional adjustment mechanism 26 includes a plurality of throughholes 1967 and 19 r 7, a plurality of pins 27, and a plurality ofsleeves 28.

As illustrated in FIG. 2, the display module 10 is attached to thesubframe 90 (the support member) of the display device via the firstattachment portion 19B0 of the blue panel frame 19B and the secondattachment portion 19R0 of the red panel frame 19R. The light guidingoptical system (not illustrated), which is the subsequent stage of thedisplay module 10, is fixed to the subframe 90, and an optical axis ofthe light guiding optical system is aligned with respect to the subframe90. The display module 10 is provided with the plurality of throughholes 1967 and 19 r 7 for attaching the display module 10 to thesubframe 90. Specifically, two of the through holes 1967 are provided inthe first attachment portion 19B0, and two of the through holes 19 r 7are provided in the second attachment portion 19R0.

Each of the plurality of pins 27 is provided at a position correspondingto each of the plurality of through holes 1967 and 19 r 7. One end ofeach of the pins 27 is fixed to the subframe 90. Specifically, whilefour of the pins 27 are fixed to the subframe 90, one of the pins 27provided in the first attachment portion 19B0 is configured by a pin 27Ahaving a surface on which a fine screw thread is formed, and theremaining three pins 27 are configured by pins 27B each having a smoothsurface on which no screw thread is formed. Hereinafter, the pin 27 onwhich the screw thread is formed will be referred to as the diopteradjustment pin 27A, and the pins 27 on which the screw thread is notformed will be referred to as the attachment pins 27B.

As illustrated in FIG. 9, one end of the diopter adjustment pin 27A isfixed to the subframe 90 via a pedestal 29. By being held by thepedestal 29, the diopter adjustment pin 27A is configured to berotatable, but not movable. Further, a groove 27 m into which ascrewdriver can be inserted is provided on the other end of the diopteradjustment pin 27A. As a result, a configuration is obtained in which,when the screwdriver is inserted into the groove 27 m of the diopteradjustment pin 27A and rotated, the diopter adjustment pin 27A canrotate without moving. In contrast, one end of the attachment pin 27Billustrated in FIG. 8 is directly fixed to the subframe 90.

Each of the plurality of sleeves 28 is provided so as to correspond toeach of the plurality of pins 27. Specifically, each of the sleeves 28is slidably attached to each of the pins 27 along an extension directionof each of the pins 27. Further, of four of the sleeves 28, a screwthread that engages with the screw thread of the diopter adjustment pin27A is formed in an inner surface of a sleeve 28A into which the diopteradjustment pin 27A is inserted. In contrast, an inner surface of sleeves28B into which the attachment pins 27B are inserted is a smooth surface.

As illustrated in FIG. 8, an inner diameter D1 of each of thethrough-holes 1967 and 19 r 7 is larger than an outer diameter D2 ofeach of the sleeves 28. In other words, a gap is provided between eachof the through-holes 1967 and 19 r 7 and each of the sleeves 28. Afteradjusting the position of the display module 10 according to a method,which will be described below, the gaps between the through holes 1967and 19 r 7 and the sleeves 28 are filled with an adhesive 31, and thesleeves 28 are fixed to the display module 10. As a result, the displaymodule 10 is configured to be movable along the pins 27 via the sleeves28.

A method for adjusting the position of the display module 10 having theabove-described configuration will be described.

First Step

First, a state is maintained in which the gap between each of thethrough-holes 1967 and 19 r 7 and each of the sleeves 28 is not filledwith the adhesive 31. In this state, the display module 10 is disposedabove the subframe 90 so that the pins 27 and the sleeves 28 attached tothe subframe 90 pass through the through holes 1967 and 19 r 7. At thistime, since there is the gap between each of the through-holes 1967 and19 r 7 and each of the sleeves 28, the position and inclination of thedisplay module 10 with respect to the subframe 90 can be adjusted withina range of the gap. In this way, of the four items described above,three items can be adjusted, which are (1) the position of the displaymodule 10 in the X and Y directions, (2) the rotation of the displaymodule 10 in the XY plane, and (3) the inclination of the display module10 with respect to the XY plane.

Second Step

Next, the gaps between the through-holes 19 b and 19 r 7 and the sleeves28 are filled with the adhesive 31, and the adhesive 31 is cured. As aresult, the sleeves 28 are fixed to the display module 10. Then, thedisplay module 10 becomes movable with the sleeves 28 along the pins 27.After the second step is completed, an optical axis of the displaymodule 10 coincides with the optical axis of the light guiding opticalsystem fixed to the subframe 90. Light emitted from the display module10 is collimated and incident on the light guiding optical system.

Third Step

Next, a focus position of the display module 10 is adjusted to adjustthe diopter. At this time, the screwdriver is inserted into the groove27 m of the diopter adjustment pin 27A, and the diopter adjustment pin27A is rotated by the screwdriver. At this time, since the diopteradjustment pin 27A and the sleeve 28A are threaded, the sleeve 28A movesalong the diopter adjustment pin 27A by a distance corresponding to therotational amount of the diopter adjustment pin 27A. Further, the sleeve28B around the attachment pin 27B also moves along the attachment pin27B in conjunction with this movement. As a result, the display module10 moves in the optical axis direction of the display module 10. In thisway, the above-described item (4), namely, the position of the displaymodule 10 in the Z direction can be adjusted.

In the display module 10 of this embodiment, the frames 19B, 19R, and19G that hold the display panels 14B, 14R, and 14G, respectively, areconfigured by three plate portions, and at a point in time before eachof the display panels 14B, 14R, and 14G is completely fixed to the prism15, even if the point in time is after the display panels 14B, 14R, and14G are held by the frames 19B, 19R, and 19G, respectively, it is stillpossible to finely adjust the position of each of the display panels14B, 14R, and 14G and perform precise positional alignment between thedisplay panels 14B, 14R, and 14G. Further, since the display panels 14B,14R, and 14G are held by the frames 19B, 19R, and 19G, respectively, itis easy to perform a positional alignment operation.

Further, the housing 12 is not a member that covers the whole of thethree display panels 14B, 14R, and 14G, but has a configuration in whichthe three frames 19B, 19R, and 19G, which individually hold the threedisplay panels 14B, 14R, and 14G, respectively, are combined together.As a result, it is possible to reduce the size and weight of the displaydevice 10. In this way, according to this embodiment, it is possible toprovide the display module 10 in which the positions of the plurality ofdisplay panels 14B, 14R, and 14G are easily aligned and which has acompact configuration.

Further, since the third plate portion 19B3 of the blue panel frame 19Bis in contact with the blue display panel 14B, the blue panel frame 19Bcan hold the blue display panel 14B in a stable manner. Further, sincethe blue panel frame 19B is formed from a metal material having a highthermal conductivity, and is thermally coupled to the blue display panel14B, heat generated in the blue display panel 14B can be conducted tothe blue panel frame 19B, and the heat can be efficiently released tothe outside from the blue panel frame 19B. As a result, an increase inthe temperature of the blue display panel 14B is suppressed, and thus,light emission efficiency and reliability of the blue display panel 14Bcan be improved. The same effect as this is achieved for the red displaypanel 14R and the green display panel 14G.

In this embodiment, the configuration in which each of the display panel14B, 14R, and 14G is directly in contact with each of the frames 19B,19R, and 19G is described as an example. However, instead of thisconfiguration, each of the display panels 14B, 14R, and 14G may bebonded to each of the frames 19B, 19R, and 19G via a thermallyconductive adhesive. Even with this configuration, effects similar tothe above-described effects can be achieved. In other words, it isdesirable that each of the display panels 14B, 14R, and 14G be thermallycoupled to each of the frames 19B, 19R, and 19G.

Further, since in the blue panel frame 19B, the step portions 19 b 6,which come into contact with the first surface 15 a of the prism 15, areprovided on the first plate portion 19B1 and the second plate portion19B2 that face each other, the blue panel frame 19B can hold the bluedisplay panel 14B in a stable manner. Further, by appropriately settingthe dimension L1 from the first surface 19Ba of the third plate portion19B3 to the step portion 19 b 6, the gap between the blue display panel14B and the prism 15 can be appropriately managed including a case inwhich the gap is zero. The same effect as this is achieved for the reddisplay panel 14R and the green display panel 14G.

Further, since the first clamping portion 23 and the second clampingportion 24 are provided in which, of the three frames 19B, 19R, and 19G,the portion of the green panel frame 19G and the prism 15 clamp theportion of the blue panel frame 19B and the portion of the red panelframe 19R, and since the through holes 19 gb and 19 gr are provided inthe first clamping portion 23 and the second clamping portion 24 and thefixing pins 21 are provided in the through-holes 19 gb and 19 gr, eachof the frames 19B, 19R, and 19G can be reliably fixed to each other, andthe mechanical strength of the housing 12 can be secured.

Further, since the display module 10 includes the positional adjustmentmechanism 26, the position of the display module 10 with respect to thesubframe 90 along the optical axis direction of the display module 10can be appropriately changed using the positional adjustment mechanism26. As a result, a user of the display device can adjust the diopterusing a simple tool, such as the screwdriver, and visibility of adisplay image can be improved.

Second Embodiment

A second embodiment according to the present disclosure will bedescribed below with reference to the drawings.

The display module 10 described in the above-described first embodimentis used in a display device to be described below.

FIG. 10 is an explanatory diagram illustrating a head-mounted displaydevice 1000 according to the second embodiment. FIG. 11 is a perspectiveview schematically illustrating a configuration of an optical system ofvirtual image display units 1010 illustrated in FIG. 10. FIG. 12 is anexplanatory diagram illustrating optical paths of the optical systemillustrated in FIG. 11.

As illustrated in FIG. 10, the head-mounted display device 1000 (animage display device) is configured as a see-through type eyeglassdisplay, and includes a frame 1110 provided with left and right temples1111 and 1112. In the head-mounted display device 1000, the virtualimage display units 1010 are supported by the frame 1110, and an imageemitted from the virtual image display units 1010 is caused to berecognized as a virtual image by a user. In this embodiment, thehead-mounted display device 1000 is provided with a left-eye displayunit 1101 and a right-eye display unit 1102 as the virtual image displayunits 1010. The left-eye display unit 1101 and the right-eye displayunit 1102 have the same configuration, and are disposed left-rightsymmetrically.

In the following description, the left-eye display unit 1101 will bemainly described, and a description of the right-eye display unit 1102will be omitted.

As illustrated in FIG. 11 and FIG. 12, in the head-mounted displaydevice 1000, the left-eye display unit 1101 includes an image displaymodule 1, and a light guiding system 1030 that guides synthesized lightLb emitted from the image display module 1 to an emitting portion 1058.A projection lens system 1070 is disposed between the image displaymodule 1 and the light guiding system 1030, and the synthesized light Lbemitted from the image display module 1 enters the light guiding system1030 via the projection lens system 1070. The projection lens system1070 is configured by a single collimate lens that has a positive power.

The image display module 1 includes the prism 15, and the three displaypanels 14B, 14R, and 14G provided so as to face three surfaces of thefour surfaces of the prism 15. The display panels 14B, 14R, and 14G areconfigured by organic EL panels, for example.

Imaging light emitted from the red display panel 14R enters the prism 15as first imaging light LR in a first wavelength region. Imaging lightemitted from the blue display panel 14B enters the prism 15 as secondimaging light LB in a second wavelength region. Imaging light emittedfrom the green display panel 14G enters the prism 15 as third imaginglight LG in a third wavelength region. The synthesized light Lb in whichthe first imaging light LR, the second imaging light LB, and the thirdimaging light LG are synthesized is emitted from the prism 15.

In this embodiment, the first wavelength region falls, for example, from620 nm to 750 nm, and the red display panel 14R emits the first imaginglight LR of red color. The second wavelength region falls, for example,from 450 nm to 495 nm, and the blue display panel 14B emits the secondimaging light LB of blue color. The third wavelength region falls, forexample, from 495 nm to 570 nm, and the green display panel 14G emitsthe third imaging light LG of green color. In this embodiment, the firstimaging light LR, the second imaging light LB, and the third imaginglight LG are light that does not have polarization characteristics.

The light guiding system 1030 includes a transmissive incidence portion1040 from which the synthesized light Lb enters, and a transmissivelight guiding portion 1050 having one end 1051 side thereof coupled tothe incidence portion 1040. In this embodiment, the incidence portion1040 and the light guiding portion 1050 are configured as an integratedlight transmissive member.

The incidence portion 1040 includes an incident surface 1041 from whichthe synthesized light Lb emitted from the image display module 1 enters,and a reflection surface 1042 that reflects the synthesized light Lbthat has entered from the incident surface 1041, the synthesized lightLb being reflected between the reflection surface 1042 and the incidentsurface 1041. The incident surface 1041 is a flat surface, an asphericalsurface, a free form surface, or the like, and faces the image displaymodule 1 via the projection lens system 1070. The projection lens system1070 is disposed obliquely so that an interval between the projectionlens system 1070 and an end portion 1412 of the incident surface 1041 islarger than an interval between the projection lens system 1070 and anend portion 1411 of the incident surface 1041. Although no reflectionfilm is formed on the incident surface 1041, the incident surface 1041fully reflects light that enters at an incident angle equal to orgreater than a critical angle. Thus, the incident surface 1041 has lighttransmissive and light reflecting properties. The reflection surface1042 is a surface that faces the incident surface 1041, and is disposedobliquely so that an end portion 1422 is located further away from theincident surface 1041 than an end portion 1421 of the incident surface1041. Thus, the incidence portion 1040 has a substantially triangularshape. The reflection surface 1042 is a flat surface, an asphericalsurface, a free form surface, or the like. The reflection surface 1042has a configuration in which a reflective metal layer made, mainly, ofaluminum, silver, magnesium, chrome or the like, is formed.

The light guiding portion 1050 includes a first surface 1056 (a firstreflection surface) that extends from one end 1051 toward the other end1052 side, a second surface 1057 (a second reflection surface) thatfaces the first surface 1056 in a parallel manner and extends from theone end 1051 side toward the other end 1052 side, and an emittingportion 1058 provided on a portion of the second surface 1057 that isseparated from the incidence portion 1040. The first surface 1056 andthe reflection surface 1042 of the incidence portion 1040 are joinedtogether via a sloped surface 1043. A thickness of the first surface1056 and the second surface 1057 is thinner than that of the incidentportion 1040. The first surface 1056 and the second surface 1057 reflectall the light that is incident at an incident angle equal to or greaterthan the critical angle, based on a refractive index difference betweenthe light guide portion 1050 and the outside (the air). Thus, noreflection film is formed on the first surface 1056 and the secondsurface 1057.

The emitting portion 1058 is configured on a portion of the lightguiding portion 1050 on the second surface 1057 side in the thicknessdirection. In the emitting portion 1058, a plurality of partialreflection surfaces 1055 that are angled obliquely in the normaldirection with respect to the second surface 1057 are arranged to bemutually parallel to each other. The emitting portion 1058 is a portionof the second surface 1057 that overlaps with the plurality of partialreflection surfaces 1055, and is a region that has a predetermined widthin an extending direction of the light guiding portion 1050. Each of theplurality of partial reflection surfaces 1055 is formed by a dielectricmultilayer film. In addition, at least one of the plurality of partialreflection surfaces 1055 may be a composite layer including a dielectricmultilayer film and a reflective metal layer (thin film) made mainly ofaluminum, silver, magnesium, chrome, or the like. When the partialreflection surface 1055 is configured to include a metal layer, it ispossible to obtain an effect of enhancing the reflectance of the partialreflection surface 1055, or to obtain an effect of optimizing theincident angle dependence or the polarization dependence of thetransmittance and the reflectance of the partial reflection surface1055. Note that the emitting portion 1058 may have a mode in which anoptical element such as a diffraction grating and a hologram isprovided.

In the display device 1000 configured in the above-described manner, thesynthesized light Lb consists of the parallel light that enters from theincidence portion 1040, is refracted on the incident surface 1041, andtravels toward the reflection surface 1042. Next, the synthesized lightLb is reflected on the reflection surface 1042, and travels toward theincident surface 1041 again. At this time, since the synthesized lightLb enters the incident surface 1041 at the incident angle equal to orgreater than the critical angle, the synthesized light Lb is reflectedon the incident surface 1041 toward the light guiding portion 1050, andtravels toward the light guiding portion 1050. Note that the incidenceportion 1040 is configured such that the synthesized light Lb that isthe parallel light enters the incident surface 1041. However, it may bepossible to employ a configuration in which the incident surface 1041and the reflection surface 1042 are configured to have a free form curveor the like, and after the synthesized light Lb, which is non-parallellight, enters the incident surface 1041, the synthesized light Lb isreflected between the reflection surface 1042 and the incident surface1041 to be converted into the parallel light while being reflected.

In the light guiding portion 1050, the synthesized light Lb is reflectedbetween the first surface 1056 and the second surface 1057, andadvances. Then, part of the synthesized light Lb that enters the partialreflection surface 1055 is reflected on the partial reflection surface1055 and is emitted from the emitting portion 1058 toward an eye E of anobserver. Further, the rest of the synthesized light Lb incident on thepartial reflection surface 1055 passes through the partial reflectionsurface 1055 and is incident on the next, adjacent, partial reflectionsurface 1055. Thus, the synthesized light Lb that is reflected on eachof the plurality of partial reflection surfaces 1055 is emitted from theemitting portion 1058 toward the eye E of the observer. This enables theobserver to recognize a virtual image.

At this time, as for the light entering the light guiding portion 1050from the outside, this light passes through the partial reflectionsurfaces 1055 after entering the light guiding portion 1050, and reachesthe eye E of the observer. This enables the observer to see the colorimage emitted from the image display module 1 and also see the sceneryof the outside world and the like in a see through manner.

The head-mounted display device 1000 according to the second embodimentis provided with the display module according to the first embodiment,and hence, provides excellent display quality.

Note that the technical scope of the present disclosure is not limitedto the above-described embodiments, and various modifications can bemade to the above-described embodiments without departing from thespirit and gist of the present disclosure.

For example, in the above-described embodiments, in the first clampingportion and the second clamping portion, a combination of the throughholes and the fixing pins is used as the configuration for mutuallycoupling the green panel frame, the blue panel frame, and the red panelframe together. Instead of this configuration, a fitting portion thatcauses the green panel frame and the blue panel frame, and the greenpanel frame and the red panel frame to be mutually coupled together maybe provided in each of the frames. The frames are mutually coupled bythe fitting portions, such as a recessed portion provided in the greenpanel frame and a convex portion provided in the blue panel frame, beingfitted to each other.

Further, as an example of the display module of the above-describedembodiments, the configuration is described in which the display moduleis provided with the three display elements configured by the bluedisplay panel, the red display panel, and the green panel, and theprism, but the display module may have a configuration in which thedisplay module is provided with two display elements and a prism. Forexample, the two display elements may be a first display element withorganic EL elements that emit blue light and organic EL elements thatemit red light provided on one panel, and a second display elementprovided with organic EL elements that emits green light.

Further, in the above-described embodiments, the configuration isdescribed, as an example, in which the display panel includes the twosubstrates, namely, the element substrate and the sealing substrate, andthe sealing substrate is bonded to the prism. However, instead of thisconfiguration, the display panel need not necessarily include thesealing substrate, and a side of the element substrate on which theorganic EL elements are formed may be directly bonded to the prism.

Further, in the above-described embodiment, as an example of the displaymodule, the configuration obtained by combining the organic EL panelsand the prism is described. However, the display element is not limitedto the organic EL panel, and a self light-emitting panel, such as aninorganic EL panel or a micro LED panel, may be used as the displayelement. Further, instead of the self light-emitting panel that emitsimaging light that does not have the polarization characteristics, adisplay element that emits imaging light that has the polarizationcharacteristics, such as a liquid crystal panel, may be used.

In addition, it is possible to change, as appropriate, the material,number, arrangement, shape, or other specific configurations of eachconstituent element of the display module and the display deviceexemplified in the above-described embodiments.

Further, examples of the display device provided with the display moduledescribed in the above-described embodiments include the head-up displayand the like, as well as the head-mounted display.

What is claimed is:
 1. A display module comprising: a display modulemain body; and a housing provided to the display module main body,wherein the display module main body includes a first display element, asecond display element, and a prism configured to synthesize first lightemitted from the first display element and second light emitted from thesecond display element, the housing includes a first frame that holdsthe first display element in a state in which the first display elementfaces a first surface of the prism, and a second frame that holds thesecond display element in a state in which the second display elementfaces a second surface of the prism, the first frame includes a firstplate portion and a second plate portion facing each other, and a thirdplate portion that couples the first plate portion and the second plateportion to each other, the second frame includes a fourth plate portionand a fifth plate portion facing each other, and a sixth plate portionthat couples the fourth plate portion and the fifth plate portion toeach other, at least one of the first frame and the second frameincludes an attachment portion for attaching the display module mainbody to a support member, the first frame holds the first displayelement in a state in which the prism is positioned between the firstplate portion and the second plate portion, and in which the third plateportion is in contact with the first display element and faces the firstsurface, and the second frame holds the second display element in astate in which the prism is positioned between the fourth plate portionand the fifth plate portion, and in which the sixth plate portion is incontact with the second display element and faces the second surface. 2.The display module according to claim 1, wherein the first frame and thesecond frame contain metal material, the first frame and the firstdisplay element are thermally coupled, and the second frame and thesecond display element are thermally coupled.
 3. The display moduleaccording to claim 1, wherein each of the first plate portion and thesecond plate portion of the first frame is provided with a step portionthat defines, by coming into contact with a portion of the first surfaceof the prism, a distance between the first display element and the firstsurface, and each of the fourth plate portion and the fifth plateportion of the second frame is provided with a step portion thatdefines, by coming into contact with a portion of the second surface ofthe prism, a distance between the second display element and the secondsurface.
 4. The display module according to claim 1, wherein the displaymodule main body further includes a third display element, the prismsynthesizes the first light, the second light, and third light emittedfrom the third display element, the housing further includes a thirdframe that holds the third display element in a state in which the thirddisplay element faces a third surface of the prism, the third frameincludes a seventh plate portion and an eighth plate portion facing eachother, and a ninth plate portion that couples the seventh plate portionand the eighth plate portion to each other, and the third frame holdsthe third display element in a state in which the prism is positionedbetween the seventh plate portion and the eighth plate portion, and inwhich the third plate portion is in contact with the third displayelement and faces the third surface.
 5. The display module according toclaim 4, wherein the third frame contains metal material, and the thirdframe and the third display element are thermally coupled.
 6. Thedisplay module according to claim 4, wherein each of the seventh plateportion and the eighth plate portion of the third frame is provided witha step portion that defines, by coming into contact with a portion ofthe third surface of the prism, a distance between the third displayelement and the third surface.
 7. The display module according to claim4, wherein the first surface and the second surface of the prism faceeach other, and the third surface is positioned in a directionintersecting the first surface and the second surface, and a firstclamping portion or a second clamping portion is provided, the firstclamping portion being configured such that a portion of the seventhplate portion and the prism clamp a portion of the first plate portionand a portion of the fourth plate portion, and the second clampingportion being configured such that a portion of the eighth plate portionand the prism clamp a portion of the second plate portion and a portionof the fifth plate portion.
 8. The display module according to claim 7,wherein the first clamping portion or the second clamping portion isprovided with a through hole, and the through hole is provided thereinwith a coupling member coupling the first frame and the third frame, andcoupling the second frame and the third frame.
 9. The display moduleaccording to claim 7, wherein the first clamping portion or the secondclamping portion is provided with fitting portions that couple, byfitting with each other, the first frame and the third frame and couplethe second frame and the third frame.
 10. The display module accordingto claim 1, wherein the attachment portion is provided in each of thefirst frame and the second frame.
 11. The display module according toclaim 1, wherein the attachment portion is provided with a positionaladjustment mechanism for adjusting a position of the display module mainbody with respect to the support member.
 12. A display device comprisingthe display module according to claim 1.